Interlaced yarn and method of making same

ABSTRACT

COMPACT MULTIFILAMENT YARN IS INTERLACED TO WEAVE SATISFACTORILY AS WARP IN AUTOMATIC POWER LOOMS WITHOUT SIZE OR TWIST. CONTINUOUS FILAMENTS HAVING AN AVERAGE STRENGTH OF AT LEAST 4.0 GRAMS PER FILAMENT, AND AT LEAST 50% HAVING A TENACITY OF AT LEAST 2.0 GRAMS PER DENIER, ARE PASSED THROUGH JET STREAMS TO PRODUCE YARN HAVING AN EXCEPTIONALLY UNIFORM BUNDLE COHESION MEASURED AFTER A BACKWINDING TEST OF STABILITY TO WORKING IN USE. THE YARN HAS A HIGHLY UNIFORM APPEARANCE FREE FROM FILAMENT   DEFECTS, E.G., NO MORE THAN 10 DEFECTS PER MILLION END YARDS OF YARN WHEN TESTED WITH A CONVENTIONAL DEFECT ANALYZER.

Feb. 16, 1971 w, GRAY 3,563,021

INTERLACED YARN AND METHOD OF MAKING SAME Filed Dec. 9, 1969 3 Sheets-Sheet 1 FIG-l INVENTOR WALTER CLARKE GRAY ATTORNEY Feb. 16, 1971 w. c. GRAY INTERLACED YARN AND METHOD OF MAKING SAME 3 Sheets-Sheet 2 Filed Dec. 9, 1969 FIG- R Y. mA n m G M H M M R m A L o l c I fi m a 2 0 .30 8 J m w ATTORNEY Feb. 16, 1971 w. c. GRAY INTERLACED YARN AND METHOD OF MAKING SAME 3 Sheets-Sheet :5

Filed Dec. 9, 1969 FIG- FIG-9 INVENTOR WALTER CLARKE GRAY ATTORNIL'Y United States Patent 01 3,563,021 Patented Feb. 16, 1971 Bee Int. Cl. D02g 3/22 U.S. Cl. 57-140 12 Claims ABSTRACT OF THE DISCLOSURE Compact multifilament yarn is interlaced to weave satisfactorily as warp in automatic power looms Without size or twist. Continuous filaments having an average strength of at least 4.0 grams per filament, and at least 50% having a tenacity of at least 2.0 grams per denier, are pased through jet streams to produce yarn having an exceptionally uniform bundle cohesion measured after a backwinding test of stability to working in use. The yarn has a highly uniform appearance free from filament defects, e.g., no more than 10 defects per million end yards of yarn when tested with a conventional defect analyzer.

REFERENCE TO RELATED APPLICATION This is a continuation-in-part of my copending application Ser. No. 801,596 filed Feb. 24, 1969, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to compact multifilament yarn for use as the warp in automatic power looms, the yarn being of a type referred to as interlaced yarn wherein individual filaments and groups of filaments are entangled with adjacent filaments and groups of filaments along the length of the yarn to form a coherent unitary strand. The invention relates more specifically to continuous filament warp yarns which have been interlaced to have a combination of properties which make them suitable for use as the warp in shuttle looms Without the need for conventional sizing operation.

Yarns to be used for warp at present are twisted or interlaced sufiiciently to prevent the yarns from becoming damage as they are handled in the operations of forming a beam and feeding the beamed yarn into the sizing operation. Sizing, or slashing (slasher-sizing), is the process of immersing warp yarns in an adhesive solution, squeezing (quetching) the yarns to distribute the solution through the filament bundle and remove excess, and drying the yarns. Some of the more common size materials are potato starch, gum, gelatin, polyacrylic acid, poly(vinyl alcohol), copolymers based on acrylic and methacrylic esters, an dispersible polyethylene.

The yarns are dried after application of size as a sheet of parallel ends (strands). Some filaments of neighboring ends adhere to each other and are often broken when the ends are separated at the split rod known as the buster bar. From 0.5 to 1.5% of molten wax by weight may be added to the yarn to improve the running properties of the yarn, and then the yarn is wound on a flanged roller known as a loom beam, which supplies warp to the loom. To withstand this slashing procedure and weave well without interlace, warp yarns usually require 57 turns per inch (196-275 turns per meter) twist plus normal amounts of size.

Alternatively, sized Warp ends are separated while wet, are partially or completely dried while separated and are recombined onto a beam after drying. This so-called wet split" process will reduce the number of broken filaments.

After sized yarn has been woven, the fabric must be scoured to remove the size as one of the first operations in fabric finishing before dyeing and other treatments can take place. Since the amount of size on warp yarn is conventionally from l.57.0% by weight of the warp yarn used, and since much of the size has been distributed within the filament bundles and dried, this scouring op eration requires considerable time, detergent, and caustic solution. The size, detergent and other materials leave the plants in waste water and eventually are discharged into streams, where detergents kill or inhibit the activities of microorganisms which break down waste and which are food for fish life. When the size materials are attacked by microorganisms, the process depletes the dissolved oxygen content of the water which is needed for a healthy stream ecology. Thus, it would be desirable to eliminate the sizing operation or at least reduce the amount of size required.

Unsized yarns have not heretofore been successful for use as the warp of a woven fabric for several reasons. During weaving, warp yarn is subjected to severe abrasion from at least three major sources. First, the shuttle which inserts the filling yarns into the fabric slides across the warp end, tending to loosen filaments from the bundle and to snag and break filaments which become loose. Second, after the filling end has been inserted, the reed, which consists of thin metal strips between one or more warp ends, pushes the freshly inserted filling yarn closely parallel to the previous filling pass and, in so doing, the reed abrades the warp yarn longitudinally. Third, the harnesses (heald frames) with their heddles (healds) move warp ends or groups of warp ends alternately above or below the shuttle path.

In most fabric constructions, the warp ends are spaced close enough together so that they rub transversely against one another each time that the harnesses reverse the warp end positions. This transverse abrasion again tends to break down the bundle coherence and to separate individual filaments from the bundle so that they can be snagged and broken by either the shuttle or the reed. The presence of broken filaments in a fabric can lower the quality to second grade. When a warp end loses coherence and filaments begin to break, damage usually accelerates rapidly with each motion of the loom, resulting in a break of the complete warp end. This stops the loom, interrupts production until the damage can be repaired, and degrades this portion of the fabric to seconds or waste. Even if filaments do not break but are merely spread apart in one end, or if slack filaments are pulled out into loops, they can tangle with those of an adjacent end so that the defective end passes on the Wrong side of the filling. This gives a fabric defect known as a float and second-grade fabric rating if severe enough.

True twist yarns which are sized are usually somewhat flattened because of the action of squeeze (quetch) rolls which remove excess size and because of the flattening effect of other rolls during sizing and drying in the drysplit process. The degree of flattening is usually quite variable. As these yarns are woven, the narrow dimensions of the warp ends can change their position randomly with respect to the plane of the fabric, creating varying gaps between ends and varying bending modulus depending upon the orientation of the narrow dimension with respect to the bending moment. The wet-split process can reduce this nonuniformity but does not eliminate it.

When the above conventional sizing treatment is used for interlaced yarn having highly-interlaced regions which absorb a different amount of size than less tightly interlaced regions, the warp yarn will be variable with respect to both filament bundle dimensions and stiffness, and highly-interlaced regions which are not as free to flatten during sizing and drying as are the regions between may also cause variations in filament bundle dimensions.

During weaving, varying filament bundle dimensions of sized warp ends may crowd neighboring warp ends or leave gaps between them, and the varying stiffness may force the filling out of its usual position. The resulting fabrics may have a non-uniform appearance characterized by streaks which can be A; to inches (0.31 to 38.1 cm.) long scattered through the surface.

In wet-split processes, sized warp ends can be partially dried under tension while out of contact with deforming surfaces. This keeps the filament bundles rounder than the dry-split process, but inevitable bundle shape variations are set into the yarn when the size drying is completed in contact with heated rolls (cans).

SUMMARY OF THE INVENTION The product of the present invention is a compact interlaced yarn which is suitable for use, without size and/or twist, as warp yarn in automatic power shuttle looms with satisfactory loom operability to produce high quality fabric. The yarn retains the properties required for such use after the yarn has been subjected to fluctuating tension and a combination of transverse and longitudinal abrasion. Fabric woven with this warp yarn can be processed by mills with less scouring and less detergent than has been required previously for removal of size, waxes, soil and the like from the woven fabric, with less stream pollution due to Waste water from scouring operations and less cost of pollution abatement facilities. The invention also provides a rapid, continuous process for producing such interlaced warp yarn. Other objects and advantages of the invention will become apparent from the specification and claims.

The surprising discovery has been made that multi-filament yarn can be interlaced to weave satisfactorily as warp in automatic power shuttle looms without size and/ or twist when the interlaced yarn is a compact bundle of continuous filaments of adequate strength, has sufficient interlace stability and has an exceptionally uniform bundle cohesion. The interlaced yarn is evaluated with an automatic pin drop counter by the APDC Test described subsequently. The average of 100 APDC readings (Y) in centimeters, and the standard deviation (:1) of the readings, are determined on a representative sample.

The yarn is evaluated for interlace stability in use by determining the above values on yarn which has been backwound with working of the yarn as described subsequently in the interlace Retention Test. The products of this invention are characterized by values of X '+o", determined to two significant figures after backwinding the yarn, of less than 0.17 (B/N)|4.0, and a coefficient of variation (if/X) of less than 0.039(d.)+0.33 and preferably less than 0.039(d.)+0.30, where i is the average of 100 APDC readings in centimeters, a is the standard deviation of the APDC readings, B is the breaking strength of the yarn in grams, N is the number of filaments in the yarn, and (d.) is the denier per filament. The breaking strength of the yarn must be at least 4.0 N and at least 50% of the filaments must have strengths of at least 2.0 grams per denier for the yarn to weave satisfactorily as warp yarn without size or twist. These products will have less than 10 defects per million end yars of yarn when tested for projecting filaments with a defect analyzer as described subsequently.

The yarn will generally consist of at least 7 filaments of l to 10 denier per filament, and is preferably of to 250 total denier, but yarns of up to 520 denier are suitable. Preferably, the filaments are composed of synthetic linear condensation polymer such as polyethylene terephthalate or polyhexamethyleneadipamide. Preferably the yarn has an interlace retention of at least 70% after the abrasionbackwinding, as determined by the interlace Retention Test described subsequently. Yarn interlaced so that the 4 above-defined value of X'+a' is less than 0.17 (B/NH-LS is desirable for the best weaving performance.

The interlaced yarn of this invention is compact. When tested as described subsequently in the compactness test, the diameter when measured at a tension of 0.1 g.p.d. is at least of the diameter when measured at 0.01 g.p.d. Conventional finishes may be used in amounts of up to about 2.5% by weight of finish nonvolatiles based on the weight of yarn, but satisfactory loom operation is obtained without size. Substances giving customary ranges of running friction between the yarn and guide surfaces, but increased static friction between filaments, may be applied to yarn either as finishes during the production step or may be applied instead of size at a slashing operation.

Most surprisingly, the appearance of fabrics made with the above yarn can be equal to or better than that of fabrics made with expensive highly-twisted sized warp yarns. Yarns prepared in accordance with this invention can be woven without size or with substantially reduced size at high efficiency to produce quality fabrics with uniform visual appearance equal or superior to the best sized yarns at similar luster levels. The slashing step is eliminated or greatly increased in speed, less wash water and detergent are used, the scouring operation can proceed more rapidly because there is little or no dried size to remove from the yarn bundle, and a single scour-dye operation becomes practical.

The compact interlaced yarn of this invention is provided by improvements in the process for spinning, drawing and interlacing synthetic polymer filaments to porduce multifilament yarn for use without any twisting operation. In one process of the present invention, the filaments are interlaced by jetting gas under a pressure of 60 to pounds per square inch gage pressure (4.2 to 7.0 kg./cm. through a pair of adjacent orifices to form intersecting streams of jetted gas, feeding a group of at least 7 filaments having an average filament strength of at least 4.0 grams per filament through the intersecting streams under a tension between 0.1 and 0.4 gram per denier to interlace the filaments into a yarn and then winding up the yarn to form a suitable package. The adjacent orifices are arranged side-by-side in an alignment perpendicular to the direction of yarn travel, e.g., as illustrated in FIG. 6 of the drawings. Yarn which weaves satisfactorily as warp in automatic power shuttle looms without twisting or sizing the yarn, and which has no more than 10 defects per million end yarns of yarn in a conventional test for projecting filaments with a defect analyzer, is produced in the indicated process by applying finish to the filaments prior to interlacing to provide between 0.3 and 3.0% by weight of finish nonvolatiles on the filaments fed to the intersecting streams and rapidly traversing the yarn from side to side so that the filaments are oscillated in the intersecting streams to produce a compact interlaced yarn characterized by having a value for X"+a' in centimeters of less than 0.17 (B/N)+4.0 and a value for 071? of less than 0.039 (d.)+0.33, where X, a", B, N and (d.) are as defined previously.

The specified rapid traverse of the yarn from side to side, so that the filaments are oscillated in the intersecting streams, can be accomplished mechanically, or pneumatically by a tandem jet arrangement. The traversing guide used for producing a cross-wound yarn package on a windup roll provides a fanning zone" in which the yarn is rapidly traversed from side to side. According to one embodiment of the invention, the intersecting streams are located so that the filaments are oscillated in the streams by this traversing action of the windup guide. Fixed guides to control the motion of the yarn can be arranged adjacent to the intersecting streams. In accordance with another embodiment of the invention, two pairs of intersecting streams are arranged in tandem to cooperate in rapidly traversing the yarn so that the filaments are oscillated in intersecting streams.

The finish may be applied at one or more locations prior to interlacing to provide the specified 0.3 to 3.0% by weight of finish nonvolatiles on the filaments fed to the intersecting streams. The finish may be applied before or after drawing, or the finish may be applied both before and after drawing. A secondary finish is normally applied after interlacing. Commercial yarns usually have 0.05 to 2.5% finish nonvolatiles by weight to reduce running friction. A secondary finish can be selected for assistance in interlace retention.

As used herein, compact interlaced yarn refers to products essentially free from ring-like or other filament loops (being thereby distinguished from bulked, textured, tousled or loopy yarns), and which meets commercial standards for freedom from broken filaments or accidental loops in conventional nonbulked yarn. In addition, the interlaced yarn must be substantially free from slack filaments. The term yarn" as used herein does not comprehend tows, which are large bundles of filaments brought together for processing treatment and subsequently drafted or cut into staple and spun into yarn for use in textile operations. The interlaced product of this invention consists of continuous filaments, which may be of the same polymer type or more than one polymer type, and the filaments may have been treated in different ways so that some filaments in the yarn bundle have different properties from others.

The lubricating finishes referred to herein are substances having the conventional functions of controlling the friction between yarn and guide surfaces or between adjacent yarns, and may reduce static electricity, but they do not appreciably adhere filaments together in the sense that sizes do, nor do they prevent yarn bundles from changing cross-sectional shape in normal textile processing operations. A convenient distinction between conventional size and finish is that a size dries to form a solid film while a finish forms a non-hardening liquid film. Certain types of finishes which aid in retaining interlace give conventional levels of running friction between yarn and guides or loom shuttle but give high static friction between filaments within the yarn bundle, inhibiting loss of interlace.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the invention and apparatus discussed hereinafter:

FIG. 1 illustrates the appearance of a typical interlaced yarn product of the present invention when floated on water before backwinding.

FIG. 2 illustrates the change in appearance when floated on water after backwinding the same yarn.

FIG. 3 similarly illustrates the appearance before backwinding of interlaced yarn not suitable for the present purposes.

FIG. 4 illustrates the appearance of the yarn product of FIG. 3 when floated on water after backwinding.

FIG. 5 illustrates schematically a process and apparatus for making interlaced nylon yarns by this invention.

FIG. 6 is an enlarged perspective view of the interlacing jet apparatus 37 of FIG. 5, shown with plate 56 partially broken away.

FIG. 7 illustrates schematically a process and apparatus for making interlaced polyester yarns by this invention.

FIG. 8 is a schematic view of an instrument for measuring interlace.

FIG. 9 illustrates equipment for backwinding yarn to determine interlace retention.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 shows the appearance before backwinding of a typical interlaced 70 denier, 34 filament yarn of this invention, having a water-soluble finish, when laid carefully in a relaxed state on the surface of a quiescent water bath. Surface tension effects cause the filaments to separate where such separation is possible, thereby revealing the tight and loose sections of the interlaced structure.

The scale is in inches. It can be seen that interlace holds the yarn bundle together almost continuously.

FIG. 2 shows the appearance after baclcwinding the above yarn and testing in the same way. The filaments are able to spread somewhat more, revealing the periodic nature of the interlace.

FIG. 3 similarly shows the appearance on water of an interlaced 70-34 nylon 66 yarn of the prior art. It can be seen that there are few tightly-interlaced regions in this length of sample, but groups of filaments are entangled randomly.

FIG. 4 shows the appearance of the yarn of FIG. 3 after backwinding and floating on water. It is evident that filaments of this yarn have considerably more freedom to separate from the bundle when abraded transversely than those of FIGS. 1 and 2.

FIG. 5 shows a typical process for spinning, drawing anl interlacing a polyamide product by this invention. Molten nylon 66 polymer is supplied through conduit 23 to pump 24 which divides the flow and supplies polymer to each of four spinnerets 25, each spinneret producing one or more groups of filaments. The filaments are cooled and solidified by air in chimney 26 and the groups of filaments are then gathered together into yarns at the bottom of the chimney before passing over the primary finish roll 27 where a first finish is applied.

A typical yarn then passes around powered feed roll 28 and freely rotating separator roll 29 in a series of wraps, the separator roll 29 being mounted at such an angle as to advance the wraps and to keep the yarns separated from each other.

The yarns then pass over freely rotating roll 30 to driven draw roll 31 which is rotating considerably faster than feed roll 28. The yarns are wrapped around draw roll 31 and associated freely-rotating separator roll 32 in several wraps, and then proceed to a pair of positivelydriven angled draw rolls 33 rotating at a faster rate than draw roll 31 so that an additional amount of drawing takes place. Rolls 33, angled to provide wrap separation, are enclosed in hot chest 34 which is supplied with heated air to stabilize (heat-set) the yarn for reducing its shrinkage.

Each yarn then passes out of the hot chest and into and through an interlacing jet apparatus 35, the majority of the air flow leaving the jet in the same direction as the yarn motion. The yarn is under sufiicient tension to prevent the formation of loops or slack filaments. The jet apparatus 35 consists of two jets of Type B as (described hereinafter) in series for each threadline (yarn path) at a center-to center distance of inch (2.22 cm.). Guide pins are provided before and after the jets to keep each yarn line properly centered in the jet. The yarn then passes over secondary finish roll 36 where an additional finish is applied.

In a preferred process of this invention, no interlacing jets were used in position 35, but instead a single jet was used in position 37. This arrangement is shown in greater detail in FIG. 6. The yarn then passes to a multiple package windup where the yarn end is wound on package 38.

FIG. 6 shows a detail of the interlacing jet apparatus when it is mounted in position 37 of FIG. 5. Yarn 52 takes a sutficient change in direction over guide pins 53 and 59 to remain in firm contact with these pins and in accurate alignment with the jet at all times. Interlacing jet apparatus 54, which consists of air hole plate 55 and backing plate 56, spaced away from but parallel to plate 55, is mounted on adapter plate 57. Air is supplied through plate 57 to the jet apparatus by a conduit not shown. A pair of guide pins 58 is positioned below the jet in such a manner that straight lines drawn tangentially from guide pin 59 to each pin 58 will pass no further from the center line of the jet apparatus than the center line of the two air holes. In the case of the jet arrangement of FIG. 7, the major axes of the ellipses formed by the intersection of the air holes with the surface of air hole plate 55 will lie on a common line and guide pin 100 is used to guide the thread lines between plates 55 and 56.

FIG. 7 shows one yarn end of a multi-end process and apparatus for spinning, drawing and interlacing polyester yarn. The molten polymer is extruded through spinneret 39, is cooled in zone and is converged into a filament bundle (a yarn) after which the yarn passes over finish roll 41, around feed roll 42 and associated separator roll 43 in a number of wraps. It then passes through the team draw jet apparatus 44 over finish roll 45 and to angled draw rolls 46 which are running considerably faster than feed roll 42. The draw rolls are mounted in hot chest 47. The yarn then passes to finish roll 48 and then through interlacing jet apparatus 49, after which it is wound on tube 50 which is driven by roll 51. The jet apparatus 49 is preferably that of FIG. 6, arranged as described in the preceding paragraph, but without lower pin 59. Alternatively, jet apparatus 49 may be replaced with a jet apparatus 99 mounted ahead of finish roll 48.

FIG. 8 shows a modification of the instrument which is described in Hitt US. Patent No. 3,290,932, the instrument being modified to provide increased accuracy for measuring interlaoe in yarns of this invention. Yarn is taken over-end from supply package through pigtail guide 61 to hysteresis brake 62 and then over guide pins 63 and 64, past needle holder assembly 65 and then through guide 66, around yarn drive roll 67 and freelyrotating separator roll 68 to waste 69. In operation, a new yarn is tied to the end of the previous sample, and the instrument is actuated to move the new sample past the needle holder assembly 65, the needle being retracted during this time. The yarn then stops automatically. The operator then pushes button 70 on control panel 71 which starts the yarn moving and also actuates solenoid valve 72 allowing compressed air from supply 73 to flow through tube 74 into the (pivoted) needle holder assembly 65 and to push a needle (not shown) forward through the filament bundle. The yarn continues to move while the needle splits the yarn bundle until the density of interlace in the yarn is sufficient to tilt assembly 65 against the force exerted by weight 75. This movement causes flag 76 to interrupt the light beam from light 77 to photocell 78 which closes solenoid valve 72, allowing the needle to retract by means of a spring and at the same time stopping motor 79. During the time that the yarn was running and the needle was splitting the yarn,

light from lamp 80 had been passing through holes in 7 disc 81 to photocell 82, and these pulses were registered of other materials which meet the specified strength requirements may also be used. Examples of suitable materials are polyamides such as nylon 6, nylon 66, poly (hexamethylene terephthalamide), and poly(metaphenylene isophthalamide). Polyesters are also suitable. By polyesters is meant fiber-forming linear condensation polymers containing in the polymer chain the carbonyloxy linking radicals Polymers containing oxy-carbonyloxy radicals are comprehe'nded within this group. In the absence of an indication to the contrary, a reference to polyesters is meant to encompass copolyesters, terpolyesters and the like. Particular crystallizable, linear condensation polyesters are polyethylene terephthalate, polyethylene terephthalate/isophthalate (85/15), polyethylene terephthalate/S- (sodium sulfo)isophthalate usually in the range of 96/4 to 99/1 mol percent, but preferably 98/2, poly(p-hexahydroxylene terephthalate), poly(diphenylolpropane isophthalate), poly(diphenylolpropane carbonate), the polyethylene naphthalene dicarboxylates (especially those derived from the 2,6- and 2,7-isomers) and poly(m-phenylene isophthalate).

Each filament may be composed of one material or of two or more different materials. However, weak filaments such as the usual textile counts of cellulose acetate and cellulose triacetate are not satisfactory materials for this invention.

Processing equipment Yarns may be spun (extruded) on one machine, then drawn and interlaced on another. The drawing and interlacing may be accomplished on draw twisters, draw winders or warp draw machines. The yarn may also be spun and drawn on one set of equipment, and then interlaced on a separate winder as an independent operation. However, a preferred method which reduces production costs is a continuous machine as described in FIGS. 5 and 7 for spinning, drawing, interlacing and winding yarn onto a package ready for shipment to the customer.

The preferred type of interlacing jet apparatus is one which has a self-oentering action, as in the case of the jets of US. Patent No. 3,115,691. Jets having dimensions listed in Table I were used in making the majority of the yarns of the present invention which are illustrated in the Examples. Jet Type A was used for the polyester yarn of Examples 1 and 3. Type B was used for 40 and 70 denier nylon. Type C, having larger dimensions, was used for 200 denier yarns of Example 6.

TABLE I [Figure numbers and reference numbers apply to U.S. Patent No. 3,115,691]

Jet type A B C Oriliees:

Number per yarn 2 2 2. Diameter, inches 0.035 (0.89 mm.) 0.035 (0.89 mm.). 0.060 (1.52 Inrn.). Air impingement, deg es (angle ,8

Fig. IV) 9O 60 (30. Distance between hole centers (meas- 0.10 (2.54 min.) 0.10 (12.54 min.) 0.178 (4.52 mire). ured at surface of Plate 12, Fig III), inches.

Ilole intersection, degrees (angle a 90 U0.

Fig. III projected on a plane perpendicular to the yarn). Surface (12) Aluminum oxide. Uncoated metal I ncuated metal. Striker plate Surface (5. Fig. I Aluminum oxide. Aluminum oxide Aluminum oxide. Orifice to striker plate. (W) in... 0.030 (0.76 mm.) 0.030 (0.76 mm.) 0.030 (0.76 mm).

on Hewlett-Packard electronic counter 83. An operator then records the number and presses button 70 to repeat the cycle. The yarn travels 7.5 cm. between the point where the pin retracts from the bundle and the pin is inserted for the next splitting.

The yarn filaments are preferably composed of synthetic linear condensation polymer, although filaments Process conditions It has been found that a number of process conditions must be closely controlled in order that the yarn produced may be sufliciently cohesive, uniform and retentive of interlace. Yarn speed, air pressure, amount of finish on yarn and yarn tension at the interlacing jet must be optimized and maintained at a uniform level. Jets should be clean and preferably be of a type which do not collect deposits of finish or other material which may interfere with the interlacing operation. The yarn itself should be substantially free from monomer or other foreign matter at the time it is interlaced. The interlacing fluid must be free of dirt or oils which can deposit on the walls of the fluid passages and change their flow characteristics. The filaments approaching the interlacing zone should be uniform along their length in mechanical properties, denier and cross-sectional shape. Yarns must be guided uniformly through zones of equal interlacing effect. All yarn guiding surfaces must be kept clean and of uniform surface roughness, particularly those which follow the interlacing operation.

The threadline should be stabilized after leaving the jet to prevent shaking out interlace. A coanda may be used at the point where the yarn enters or leaves the jet to direct the exiting air flow away from the yarn line.

Air pressure must be between 50 and 150 pounds per square inch gage (p.s.i.g.) (3.5 to 10.5 kg./cm. gage), and preferably between 60 and 100 p.s.i.g. (4.2 to 7.0 kg./cm. gage) for the jet types described above in order to make the product of this invention. When operating within the preferred pressure range, the interlace level is relatively insensitive to tension fluctuations. Preferably the yarn tension in the jet is between 0.1 and 0.4 gm./ den., finish on yarn at jet is between 0.3 and 3.0% nonvolatiles by weight, yarns are aligned accurately on center of the jet for the tandem arrangement, or are arranged so the yarn center line is midway between the two parallel plates in the fanning arrangement illustrated in FIG. 6. If a type of jet is employed wherein the zone of uniform interlacing action is not at the center, the yarn should be maintained in the zone of uniform action by suitable guides, high tension or other means. False twisting must be avoided so that there is no fluctuation in the freedom of filaments to separate and interlace at the jet.

The tension on the yarn is more than sufficient to prevent the yarn from escaping from the zone of uniform interlacing and prevent slackness and the development of loops, crimps or coils in the yarn due to the fluid action.

Because the jet apparatus of US. Pat. No. 3,115,691 has a self-centering action tending to force the yarn toward the center of the jet, the interlacing action appears to be intensified when the yarn is forcibly pulled toward one or the other of the intersecting air streams. Therefore, the arrangement shown in FIG. 6 was found to give yarn of tighter cohesion. It should be noted that the pair of pins 58 permit only a small amount of motion to the yarn line while the traversing action of the windup moves the yarn a much larger amount; therefore,

the yarn in the interlacing zone runs a majority of its time toward one extremity or the other of its motion and crosses the center line during a relatively smaller portion of the total cycle time. However, as the yarn traverses on the package, the tension normally rises as the yarn approaches the ends of the package because it has to travel a greater distance. This higher tension would inhibit interlacing to some degree if the yarn remained in a zone of constant interlacing energy, but by moving the yarn into a zone of more intense interlacing action, the effect of the higher tension is largely or completely offset, thus giving interlace which is relatively unaffected by the traverse cycle.

On the other hand, uniform interlace may be produced if tension fluctuations are reduced or eliminated. In the case of the arrangement shown in FIG. 6, pins 58 tend to reduce the magnitude of the tension fluctuations as measured at the jet by snubbing the yarn. When the jets are located above the secondary finish roll in position 35 of FIG. or position 99 of FIG. 7, the drag of the yarn on the finish roll dampens tension fluctuations. Tension may be made almost completely uniform if one or more driven rolls is interposed between the interlacing apparatus and the windup.

Two interlacing jets in tandem may be used in position 35 of FIG. 5 or position 99 of FIG. 7 where the yarn is not traversed by the windup. In this case, the yarn is guided constantly into the center of the jet apparatus where it is subjected to the dampened fluctuating tension described above. However, the two jets cooperate to produce interlace of degree and uniformity which cannot simply be obtained by using more air in a single jet. While the preferred type of jet keeps the yarn generally centered between the two fluid streams, the turbulence is unstable and continuously moves the yarn back and forth between the two streams. Thus, the threadline oscillation produced by one jet acts to traverse the yarn between the orifices of the other jet in a somewhat similar manner to the action of the windup traverse but at a much higher frequency. Guides should not be placed between the two jets in a way which eliminates the traversing action. Tandem jets should not be located so close together that the air exhausting from one disrupts the interlacing or centering action of the other. Tandem jets may be used in position 37 of FIG. 5 or position 49 of FIG. 7.

Materials known as finishes are applied to yarns of this invention before and/or after interlacing at two or more locations. Finishes are substances having the conventional functions of controlling the friction between yarn and guide surfaces or between adjacent yarns, and may reduce static electricity, but they do not appreciably adhere filaments together in the sense that sizes do, nor do they prevent yarn bundles from changing cross-sectional shape in normal textile processing operations. A convenient distinction between conventional size and finish is that a size dries to form a solid film while a finish forms a nonhardening liquid film which, in some instances, may have high viscosity. Commercial yarns usually have 0.05 to 2.5% finish nonvolatiles by weight.

It has been found that the amount and uniformity of the finish applied to the yarn before it enters the interlacing jet has a distinct influence on the degree and uniform ity of the interlace which the yarn displays immediately after interlacing and on the retention of interlace through processing. In view of this, the uniformity of application of the finish can be seen to have a large effect on the uniformity of the interlace produced. Either too much or too little finish, therefore, is to be avoided. Finish which is or may be applied after interlacing also has an effect on the interlace since the purposes of this additional finish are to lubricate the yarn surface and reduce abrasion and/or improve the interlace retention. Varying application of this secondary finish can, therefore, cause nonuniform abrasion of the yarn in subsequent handling and nonuniform loss of interlace. Furthermore, the uniformity of the interlace can affect the uniformity of the secondary finish pick-up because yarn having different degrees of interlace will pick up varying amounts of secondary finish and such finish will be distributed on the yarn depending on the degree of interlace.

Among many methods which may be employed to improve the uniformity of finish application, a preferred one used to make most of the yarns of the examples is to dilute the finish solution and run the finish rolls faster than normal so that the finish will coat all areas of the strand more uniformly while applying the desired amount of or concentration of nonvolatiles on the yarn. For example, prior commercial yarns were made with finish concentrations of 12-20% whereas those of Examples 25 to 27 had concentrations of 210%. The term nonvolatiles is defined as materials which are not appreciably volatile at C. and thus remain on the yarn after evaporation of the water or other medium in which they are applied.

Certain types of finishes are preferable for retaining interlace. Certain ones reduce the friction between the yarn and guides and between yarn and other yarn, thus reducing the force which tends to remove interlace and separate filaments from the yarn bundle. Other finishes increase the static coefficient of friction between filaments of a given yarn bundle so that they are less likely to slide over each other as they must do in losing interlace. Still other materials may bond the filaments lightly together but in such a way that the yarn bundle cross-section may change shape and conform to the weave of the fabric and the yarns are not substantially stiffened by the finish. Materials which have a high viscosity when dry may be useful. Materials having a high degree of thixotropy may give a desirable combination of high static friction but low dynamic friction. Waxes have high viscosity between filaments but give low dynamic friction and good resistance to abrasion in the loom during weaving.

The composition of some types of finishes used in the examples are shown in Table II; volatile components of finish solutions are not included.

Table lI.Finish compositions Type M: Percent Sulfated peanut oil and oleyl triglycerides 24.0 Diethylene glycol 2.1 KOH (45%) 2.1 Highly refined mineral oil 51.3 Oleic acid 11.7 Triethanolamine 4.4 Na salt of orthophenyl phenol (40%) 4.4

Type N:

Polyethylene glycol diester 85.9 Oleic acid 2.9 Monoand di-oleyl acid orthophosphates 8.1 KOH (45%) 3.1

Type P:

Butyl stearate 74.7 POE sorbitol hexaoleate 3.9 Fatty acid esters of higher polyglycols 8.1 Oleic acid 2.3 Monoand di-oleyl acid orthophosphates 7.4 KOH (45%) 3.6 100.0

Type Q:

Polyethylene glycol diester 70.0 Fatty acid esters of higher polyglycols 30.0 100 0 Type R:

Type P (on dry basis) 60 Polyacrylic acid (on dry basis) 40 100 Type S:

Atlantic wax 131 (a paraffin wax) 40.4 Petrolite C-7500 (modified oxidized Fischertropsch Wax) 22.4 Alfonic 1618C-7 nonionic (mixed 160-l8 carbon primary alcohol ethoxylate) 22.4 Ethomeen 18/15 (ethoxylate stearyl amine) 4.44 Potassium hydroxide (45%) 0.36 Rhoplex V-336 (proprietary acrylic polymer dispersion) 100.0

Type T:

Ucon 75H90,000 (copolymer of ethylene oxide and propylene oxide) 97.0 lgepal C0630 (ethoxylated l910 mols] nonylphenol condensate) 3.0 100.0

After-treatment When weaving is completed, the fabric is scoured to remove normal yarn finish, size, afterwax, etc., and accumulated handling dirt. It is at this stage that the fabric finisher obtains his saving from the use of nonsized interlaced warp yarns. The fabrics may be dyed and scoured simultaneously.

Some yarns of the present invention may be suffciently uniform to weave satisfactorily and yet may have a nonuniform or flashy appearance in certain fabric constructions. Several techniques used by commercial dyers may be used to minimize flashes and improve fabric uniformity. These include employing leveling type dyes, specially serrated log rolls in the dye bath which work the filaments in the fabric to remove interlace nodes, and caustic presoaks and caustic scouring procedures which also work the filaments in the fabric.

YARN PRODUCT The product of this invention is a continuous filament yarn in which the filaments are interlaced to form a coherent structure, the filaments making some small angle with the filament bundle axis. A tightly-interlaced region may be analogous to a hair braid except that the number of filaments in the partici ating groups will vary. Individual filaments and groups of filaments may be ran domly entangled with adjacent filaments and groups of filaments almost continuously along the length of the yarn, but more frequently the interlace is of a *periodie" type in which a region of tight entanglement is followed by a region of little or no entanglement in which the filaments are substantially parallel to the yarn axis and are not held together in this region. For either the continuous or periodic type of interlace to be satisfactory for weaving without size, the coherency must be such that when a pin is inserted in the yarn as described hereinafter the yarn line will not split for any substantial distance before encountering a region of tight entanglement. If entangled regions are not uniformly present at sufficient frequency, long sections of filaments can easily be pulled out of the bundle by the transverse motion of the shuttle. Futhermore, the interlace must be sufficiently permanent to prevnt the yarn from losing substantial coherency during weaving so that filaments do not become free to be snagged and broken by the loom.

More uniform coherence is required for weaker filaments, and filaments of some materials are so weak that interlacing for satisfactory weaving without size is impractical. For example, cellulose acetate yarns having interlace measurements and freedom from loops or broken filaments within the apparently acceptable range for products of this invention produced so many broken filaments during weaving attempts as to be rated inoperable. It has been found that at least of the filaments in a strand must have a tenacity of 2.0 grams per denier or more to be suitable for this invention.

Yarns which develop loops during processing and weaving, for instance, under alternate stretching and relaxing, are not suitable. A mixed yarn of cellulose tri acetate filaments and nylon filaments is one such material.

An interlaced yarn of this invention has lower running friction than interlaced yarns of the prior art because of less guide-to-yarn contact due to the tighter, rounder bundle shape and the rougher bundle surface configuration contributed by the interlace. The more entangled the yarn is, and the closer together such entanglements become, the lower the friction, On the other hand, if a yarn had a substantial section without any interlace, the friction of this section would be higher and this would contribute to pulling and snagging of filaments. A low denier yarn of few filaments, where frequent entanglements are more difiicult to produce, is likely to have worse performance than a large denier yarn with many filaments, where the statistical probability of entanglements is much higher. On the other hand, more filaments do not necessarily insure good weaving performance if the denier per filament and, therefore, the filament strength is reduced. It has been found that yarns which contain slack or loopy filaments are much more likely to have such filaments pulled and broken than yarns which do not. This invention is limited to yarns normally used for textile weaving. Denier per filament may range from 1 to 10 and filament bundle denier preferably ranges from 20 to 250, but may be as high as 520.

The filaments must be continuous; staple yarns are excluded. The feed yarns must have zero-twist or degrees of producer twist less than 1 t.p.i. (39.4 turns per meter) at the time they are interlaced Filaments of more than one material may be combined either by spinning the different materials simultaneously and combining them int-o one yarn, or by combining filaments of two or more different materials by taking previously prepared yarns off packages. Filaments of one or more materials may be separated into groups so that a portion of the bundle has a different treatment from the rest and the components may then be intermingled and interlaced into a single bundle. In the case of mixed or combination yarns, the minor component may be a single monofilament. Such yarns must be produced so that all filaments are at ap proximately equal tension, because a low tension component would tend to protrude from the filament bundle as loops when tension is released. In addition, the elasticity of the components must be such that one component is not stretched beyond its elastic limits by normal processing tensions, since that would cause the yarn to become loopy during weaving.

The filament cross section may be round or non-round. Certain filament cross sections may be particularly suitable for this invention in that they reduce friction between the yarn and loom, or in that they permit filaments of a given bundle to lock together so that interlace is retained well.

The products of this invention provide woven fabric of high quality. The warp ends maintain a relatively uniform spacing from each other because the filament bundle is not stiffened by size and the filaments are free to rearrange themselves as the fabric construction requires, Which is not true of slasher sized yarns. In addition, the bending behavior of the warp yarn is relatively uniform along the ends, which is not true of highly interlaced yarns which have been sized at conventional size levels. As a result of this greater compliance, the interlaced warp yarns disclosed herein produce fabrics whose uniformity to the eye is equal to or better than that of the finest quality fabrics made with sized yarns at similar luster levels, particularly expensive yarns having high twist in an attempt to produce round, uniform filament bundles.

Since freedom of the filament bundle to bend and deform is a key to the improved fabric appearance obtainable by means of this invention, it follows that many of the benefits can be obtained by particular combinations of important factors. For example, the performance of yarns having interlace properties which are not quite satisfactory for use in shuttle looms without size can be made acceptable by adding a very small amount of conventional size or other adhesive which is deposited mostly on the bundle surface and thus does not stiffen the yarn appreciably, but which helps to improve the cohesion (sticking together) between the surface filaments. Elastic size or cohesive finish can have the same effect, whether concentrated near the bundle surface or impregnated through the bundle. Materials which form gels instead of solid or liquid films are also useful. Treatments which generally reduce friction between the yarn and the loom parts improve weavability. When yarn is to be treated by the addition of only small amounts of size or wax which may be dried rapidly, the yarn producer can apply such materials during the spinning, drawing and interlacing process, thus eliminating the need for any twisting or slashing operation by the customer. Alternativcly, the customer can apply small amounts of such materials at greatly increased slashing speeds.

In addition to the effects which various finish types may have on the yarn performance in the loom, ingredients which increase the static friction between filaments but still have low dynamic friction with textile machinery can improve the interlace which a yarn obtains at the interlacing operation and retains during subsequent processing operations, if the finish is applied either before or immediately after the interlacing jet. Any treatment which reduces friction between yarn and loom parts or other yarn can reduce loom damage to yarns, and such treatments may include modifications of the filament compositions or surface configuration as well as topical applications.

Although this invention is primarily concerned with providing that combination of properties which is necessary for making a yarn suitable for direct weaving without size in shuttle looms, the interlaced yarn product is also particularly suitable for use as the warp of water jet looms. Such looms are rapidly coming into use because of their higher operating speeds and greater simplicity of operations than shuttle looms. However, when sized warps are used in these looms, the water used to propel the filling yarn softens the size and then, if the looms stop for any appreciable length of time, the size can dry again, fixing the warp yarns in their configurations at time of stoppage. When the loom starts again, the ends are found to be distorted at the point of stoppage, and adhesions between ends must be broken. An undesirable difference can be seen between the fabric woven before and after a stoppage which persists until the warp ends have become uniformly soft again. Stop ping a loom using unsized interlaced warps creates no adhesion or variations in the yarn stiffness.

Since a water jet loom, having no shuttle, abrades the Warp yarn less than does a shuttle loom, yarns with somewhat lesser degrees of interlace coherency uniformity and interlace retention can be used without size with the water jet loom than with the shuttle loom for equivalent performance. On the other hand, the same degree of interlace as that suitable for shuttle-loom warps can be used for obtaining maximum water jet loom performance and fabric quality.

Water jet looms may provide flash-free fabric without special scouring and dyeing procedures. It is believed that when the warp yarn is wet by the water jet, the interlace nodes are reduced in intensity due to the working of the heddles (healds) as the shed reverses.

A highly interlaced yarn of this invention can be used to replace 5-t.p.i. true-twist yarn in the filling of a fabric where twisted warp and filling are normally needed to prevent raveling of the edges of the fabric when it is cut into complex shapes for shoe linings. The interlace gives satisfactory resistance to raveling. Where filling flashes are unacceptable, they may be masked by using spun staple warp yarns, or by constructing warp face satins.

Products of this invention also improve warp knitting performance, more than doubling the quantity of fabric made between yarn breaks. They may also replace highly twisted yarn in Raschel knitting and Leavers lace. Products of this invention further reduce costs of mill processes by permitting higher running speeds during beaming and rebeaming, because of reduced damage provided by the greater coherency and uniformity.

YARN TESTING PROCEDURES Filament strength and tenacity Tensile properties are determined in conventional manner, using an Instron Tester or equivalent equipment. Average filament strength is defined as equal to 15 the measured bundle breaking strength (B) divided by the number of filaments (N). The average filament strength determined in this manner is usually lower than that derived from breaking individual filaments because the weakest filaments in a bundle determine the bundle failure point. It is these same weakest filaments which initiate weaving defects.

Compactness For the purpose of this invention a compact yarn is defined as one whose diameter when measured at a tension of 0.1 g.p.d. is no less than 90% of its bundle diameter when measured at 0.01 g.p.d. tension. After first removing and discarding the outer wraps of a yarn package, approximately one yard of yarn is cut from the package and attached to the yarn clamp at the digital counter end of a Suter Twist Counter. The movable yarn clamp assembly is removed and the other end of the yarn is then strung under and over the two pulleys and a weight is attached sufiicient to provide a load of 0.01 g.p.d. tension in the yarn sample between the clamp and the first pulley. If the yarn contains twist, the twist is reduced to zero. The diameter of the yarn bundle is then measured at ten consecutive one-inch points beginning five inches away from the Twist Counter clamp, using a microscope with 3.5x objective lens and calibrated eye piece (e.g., l2.5 Filar Micrometer). The yarn is then loaded sutficiently to produce 0.1 g.p.d. tension and the diameter measurement is repeated. compactness (in percent) is then computed from the ratio of average diameter at 0.1 g.p.d. divided by the average diameter at 0.01 g.p.d. multiplied by 100. If this value is less than 90% the sample is outside the scope of this invention.

Backwinding test for interlace retention Experience with handling interlaced yarns has shown that a disc tensioner has a fairly severe effect on properties of the yarns, tending to comb out interlace, and that interlace measurements made after backwinding through a disc tensioner can provide a highly significant indication of the behavior of yarns in warp weaving. Disc tensioners are normally used when yarn is taken off the package in a creel to form a beam for warping. The reed in the loom has a somewhat similar effect. Therefore, the equipment shown in FIG. 9 (a disc tensioner made by the Cocker Manufacturing CO., US. Pat. No. 2,581,142) is used to work the yarn as the test of interlace retention. Yarn 84 is taken over-end from package 85, mounted horizontally back of disc tensioner assembly 86 which is made by the Cocker Manufacturing Company. The yarn passes through guide hole 87, around matte surfaced pin 88, and between matte surfaced discs 89. It then passes around matte surfaced pin 90 and between matte surfaced discs 91. Disc mounting assembly 92 is positioned in the fourth stop away from and including hole 93. Weights are added to discs 89 and 91 equally to attain a yarn tension of 0.3 gm./den. in the yarn as it leaves the second disc 91. The yarn passes through hole guide 94 and over freely rotating roll 95 to the tension control roller 96 of a Leesona Model 959 winder, which winds the yarn onto a paper tube 3% inches outside diameter by 11 /2 inches long (7.93 x 29.2 cm.). The winder is set to run at a constant speed of 400 yards per minute (366 meters per minute).

The yarn interlace is evaluated by making APDC measurements (described below) before and after backwinding the yarn. Percent interlace retention is defined as (X/IY'HIOO), where Y and X are the average APDC readings before and after backwinding.

APDC evaluation of yarn structure The automatic pin drop counter (APDC), disclosed in FIG. 8 and the description thereof, is used to evaluate the interlaced structure of the yarn. Several modifications of the basic instrument of Hitt U.S. Pat. No. 3,290,932 were made to provide the precision of measurement required. Hysteresis brake 62 is adjusted to give a tension of 10:1 gram between the needle holder assembly 65 and the drive roll 67. Weight on the pivoted needle is set to give 8:0.5 gram interlace entanglement force required to tilt the needle holder assembly. Disc 81 has holes and drive roll 67 has a circumference of 100 mm. so that photocell 82 receives one pulse for every millimeter travel of the yarn, which travels at the rate of 250 centimeters per minute. The amount of movement of the needle required to interrupt the light from light 77 is 0.5 to 1.0 mm. The yarn travels 7.5 cm. between the point where the needle retracts from the filament bundle and the needle inserts to start the next measurement. The operator records 100 readings (X) for each yarn sample and averages them to obtain X expressed in centimeters. The standard deviation (a) of the readings is calculated by the formula,

r N N where N is the number of readings. The percent coefiicient of variation (CV) is calculated as (ah U000). An Olivetti Underwood Programmer was used to make these calculations of Y, a and CV for the examples given subsequently. Values for yarn which has been backwound are designated i, a and CV.

As a result of extensive weaving experiments conducted as illustrated in the examples, it has been found that yarns which weave well without size have interlaced structures characterized by low values for the sum of X and a after backwinding as described in the test for interlace retention, and that lower values are required with decreasing filament strength as specified in the formula.

In addition, the coefficient of variation (CV), which is the ratio of 071 must be smaller on yarns of low denier per filament than on ones having large filaments. Yarns of the present invention have distribution curves of APDC readings after backwinding which approach normal bell-shaped distributions, whereas yarns of the prior art show skewed distributions. This diflerence is highly significant, indicating that prior art yarns have occasional regions of insufficient interlace to protect the filaments from being snagged and broken in weaving. The CV limitation specified for the yarns of this invention insures that yarns having low I? but high a skewed distributions (permissible under the formula of 'X'|-a') are excluded.

Defect analyzer test The quality of yarns is usually monitored during beaming operations to detect defective yarn ends that would cause unsatisfactory weaving performance. A widely used instrument is the Lindly defect analyzer, which projects a light beam across all of the warp yarns in the plane of the warp sheet and receives the light beam on the opposite side of the warp in a photoelectric cell, Broken filaments or other defects projecting from the warp will reduce the intensity of light reaching the photoelectric cell. The instrument can be arranged either to register such defects on a counter or to stop the warper so that defects can be removed. For the present test a Lindly defect analyzer (1000 series) is set so that a 6% change in light intensity, caused by yarn defects, is registered on a counter. The number of defects per million end yards (MEY) is calculated by dividing the number of defects by the number of end yards monitored (expressed in millions). End Yards is the product of the number of yarns (ends) being monitored multiplied by the number of yards.

Yarn inspection Visual inspection methods are used by yarn producers to reject yarns having defects which would later be caught by the above defect analyzer. Packages of yarn ready for shipment to a customer are inspected visually under a bright light against a dark background. The entire outer circumference and ends of the package are inspected for protruding filaments. The package is rejected if more than 3 such defects per 10-pound package can be seen With unaided eyes by an operator having average eyesight.

The presence of inherent loopiness or slack filaments which could result in defects when the yarn is subjected to alternate tensioning and relaxing, during processing by the customer, may be detected by the following inspection: After the outer wraps have been stripped from a yarn package to eliminate handling defects, a section of yarn approximately one yard long is cut and one end is attached to the yarn clamp at the digital counter end of a Suter twist counter. The movable yarn clamp assembly is removed and the other end of the yarn is then placed under and over the two pulleys at its opposite end and sufiicient weight is attached to the free end hanging vertically to provide a load of 0.01 g.p.d. Caution should be exercised to overcome pulley friction to insure that the yarn load is distributed to the zone to be examined. The yarn is examined at 5 to X magnification for filaments or groups of filaments projecting from the bundle surface more than one bundle diameter. The diameter measurement to be used is the diameter determined at 0.01 g.p.d. tension as in the compactness test. If more than one projecting filament is detected within a -inch region of the section between the clamp and the first pulley, the yarn is rejected for inherent loops. If only one loop is observed, additional lengths of yarn should be inspected and tested for compactness. A microphotographic montage of the sample is helpful for comparative studies.

SPECIFIC ILLUSTRATIONS The following examples illustrate specific embodiments of this invention:

Example 1 Apparatus for spin-drawing and interlacing yarn in a continuous process is set up as shown in FIG. 7. Polyethylene terephthalate having a relative viscosity of about 26 and containing 2% titanium dioxide as a delustrant is melt spun into 34 round cross-section filaments per yarn. The yarn is protected by a water base finish applied by roll 41 in the amount of about 0.6% non-volatiles by weight. The finish consists of about 65 parts by weight of refined coconut glycerides, 15 parts of sulfated glyceryl trioleate, 10 parts of nonylphenol polyethyleneoxyethanol (5-6 moles of ethylene oxide per mole of nonylphenol), 10 parts of a mixture of (mono and di) glyceryl oleates, 1 part triethanolamine, and 1 part oleic acid. At the time of application, the finish consisted of 3.5% solids and 96.5% water.

Yarn is fed by roll 42 to jet apparatus 44 at a speed of 879 yards per minute (804 meters per minute), drawn to a denier of 70 at 3050 yards per minute (2789 meters per minute) and treated again with finish, applied by roll 45, at about 3.5% conc., since the finish applied by roll 41 is substantially removed by jet apparatus 44. Finish applied at roll 45 provides about 0.6% nonvolatiles by weight of treated yarn and has the same composition as the finish applied by roll 41. Draw rolls 46 are heated to about 121 C. Finish roll 48 applies about 0.7% finish nonvolatiles by weight of yarn. The finish applied by roll 48 consists of about 6 parts by weight of nonylphenol polyethylene-' oxyethanol (5-6 moles of ethylene oxide per mole of nonylphenol), 65 parts of isobutyl stearate, 10 parts sodium dioctylsulfosuccinate, 6 parts of 3 mole ethoxylate of mixed (ll-15 C) secondary alcohols, 11.7 parts of free acid of phospholated mixed (ll-l5 C) secondary alcohol ethoxylate (3E0), and 1.3 parts of potassium hydroxide, all diluted to 18-20% solids. Draw jet 44 is supplied with steam having a temperature of 190 C. and a pressure of 50 pounds per square inch gage (3.5 lag/cm. gage).

The yarn is drawn in its passage through jet 44 and annealed in its passage over rolls 46. Treated yarn from the finish roll 48 is passed through interlacing jet 49, Type A in Table I, where interlacing of the filaments in the bundle is caused by at least 92:2 pounds per square inch gage (6.4-+ 0.14 kg./cm. gage) pressure compressed air measured by the jet. The interlace jet is mounted inside an enclosure equipped with suitable guides to position the yarn in the interlace jet for optimum interlacing. The interlace jet and enclosure are mounted between roll 48 and roll 51 so that the yarn will oscillate back and forth between and over a pair of jet orifices as disclosed in FIG. 6. A yarn traversing mechanism is provided between the interlace jet 49 and roll 51 to provide desired package formation and oscillatory motion of the yarn in the jet. This mechanism provided about 785:25 movements of the yarn to the right and 785125 movements to the left per minute to build a suitable package on a 2 inch (5.8 cm.) outside diameter and 11 inch (27.9 cm.) long tube. Windup tension of the yarn between roll 48 and package 50, driven by roll 51 at about 2950 yards per minute (2697 meters per min.), is about 17:3 grams as measured just after the jet by conventional tensiometers. Unique interlaced yarns having surprising uniformity and retention of cohesion were produced with about 4 grams per denier tenacity, 30% elongation, 8% boil-01f shrinkage, 14% dry heat shrinkage measured at 196 C., and about 1.2% total finish non-volatiles by weight of yarn. All packages were examined for yarn defects as previously described and passed first-grade visual yarn inspection standards. APDC measurements on this yarn are presented in Table III.

TABLE III IAPDC (100 readlngsfl Eight hundred packages of the new interlaced yarn were stocked on a commercial creel and used to prepare section beams, with 15,000 yards and 800 ends per beam, on a commercial warper. Yarn was removed from the supply packages on the creel by an over-end take off. A Lindly defect analyzer set to detect 6% change in light intensity registered O.97 defects per million end yards. Eight section beams were mounted on a commercial slasher and a 6,000 yard warp with 129 warp ends per inch was rebeamed directly to a loom beam without the addition of twist or size. Approximately 1.0% afterwax was added to the warp sheet on the slasher. The material was Seyco H (Seydell-Woolley and Co.) having a needle penetration value of 19 (ASTM). It was applied as a melt, leaving a high-viscosity deposit between filaments when cooled and producing a surface coating which protected the yarn from abrasion. The loom beam was mounted on a commercial Draper XD shuttle loom and a -inch wide fabric was woven at 192 picks per minute with 129 ends per inch of the interlaced denier, 34 filament yarn warp and 46 picks per inch of 2 ply 26/1 singles 65%/ 35% polyester staple/cotton blend fill yarn. The weaving efiiciency was about Example 2 In another run with the same warp construction described above, about 1.5% size on yarn by weight was applied to a 2,000-yard Warp sheet in a wet split slashing process which partially dried the ends while separated. The fabric was woven as described above and weaving efficie'ncy reached the surprising and unexpected level of 96% with no yards of fabric seconds. This yarn had about 1% afterwax. The unique interlaced yarn of this example permitted substantial reduction in percentage of size on yarn conventionally used, and slashing speeds were increased from 50 yards per minute (46 m.p.m.) for commercial operation to yards per minute (114 m.p.m.).

Example 3 Apparatus for spin-drawing and interlacing yarn in a continuous process is set up as shown in FIG. 7. Polyethylene terephthalate having a relative viscosity of about 26.5 and containing 0.3% titanium dioxide as a delustrant is melt spun into 34 round cross-section filaments per yarn. The air-quenched yarn 40 is protected by a Water base finish applied by roll 41 in the amount of about 1% non-volatiles by weight. The finish consists of about 1 part by weight of triethanolamine, 1 part oleic acid and 245 parts sodium dioctyl sulfosuccinate, 49 parts of isocetyl stearate and 24.5 parts of stearyl alcohol with 3 moles of ethylene oxide applied at about 9% concentration. From finish roll 41, yarn 40 is fed by roll 42 to jet apparatus 44 at a speed of 874 yards per minute (799 m.p.m.), drawn to a denier of 70 at 3200 yards per minute (2926 m.p.rn.) and passed over draw rolls 46 in helical wraps. Rolls are heated to about 116 C. and the yarn has about 0.4% finish nonvolatiles by weight, since a substantial amount of finish is blown off in jet 44. The jet 44 is supplied with steam having a temperature of 200 C. and a pressure of 70 pounds per sq. in. gage (4.9 kg./cm. gage). The yarn is drawn in its passage through jet 44 and annealed in its passage over rolls 46. Finish roll 45 was not used. Yarn leaving rolls 46 passes over finish roll 48 where about 1% finish nonvolatiles by weight of yarn is applied. The finish applied by roll 48 consists of about 3.4 parts by weight of triethanolamine, 8.2 parts oleic acid, 0.8 part potassium hydroxide, 62.6 parts butyl stearate, 1.8 parts diethyleneglycol, 20.5 parts sulfated peanut oil and 1.7 parts orthophenyl phenol applied at 18-21% concentration. Treated yarn from roll 48 is passed through Type A (Table I) interlacing jet 49 where interlacing of the filaments in the bundle is caused by at least 91:2 pounds per sq. in. gage (6.4:0.14 kg./cm. gage) pressure compressed air measured at the jet. The interlace jet is mounted inside an enclosure equipped with suitable guides to direct the yarn into and out of the enclosure and to position the yarn in the interlace jet for optimum interlacing. The interlace jet enclosure is connected to an exhaust system to remove air, liquid finish and finish mist from the enclosure. The interlace jet (FIG. 6) and enclosure are mounted between roll 48 and roll 51 so that the yarn will oscillate back and forth between and over a pair of interlace jet orifices for each yarn. A yarn traversing mechanism (not shown) is provided between the interlace jet apparatus 49 and roll 51 to provide desired package formation and oscillating motion of the yarn in jet 49. The mechanism provides about 920:20 movements of the yarn to the right and 920:20 movements to the left per minute to build a suitable package on a 2%; inch (5.8 cm.) outside diameter and 11-inch (27.9-cm.) long tube. Tension of the yarn between roll 48 and package 50, driven by roll 51 at about 3083 yards per minute (2819 m.p.m.), is about 17:3 grams as measured just ahead of the jet by conventional tensiometers. Unique interlaced yarns having surprising uniformity and retention of cohesion were produced with about 4 grams per denier tenacity, 31% elongattion, 8% boil-off shrinkage, and about 1.2% finish based on the Weight of yarn. APDC measurements are given in Table All packages were examined for yarn defects as previously described and passed first-grade visual yarn inspection standards. During beaming of this yarn, a Lindly defeet analyzer set to detect 6% change in light intensity registered 0.55 defects per million end yards.

Polyhexamethyleneadipamide having a relative viscosity of about 40 and nominal level of 0.5% titanium dioxide as delustrant is spun-drawn to 70-denier, 34-filament nylon yarn and interlaced on the equipment of FIG. 5 according to the process conditions described in Table V. The yarn properties appear in Table VI. The yarn is placed on a beaming creel and is section-beamed on a commercial warper with the following beaming conditions:

Beam54 inch x 30 inch Speed-600:10 y.p.m. LeaseStandard Ends790/ beam The tension on each end is controlled by disc tensioners located on beaming creels.

The quality of the yarn is analyzed during section beaming on a Lindly defect analyzer (1000 series) located just before the Windup and set to detect 4.4% or more change in light intensity caused by defects in the yarn. The defects of the yarn are recorded on the Lindly defect analyzer without stopping the beaming operation and are 1.1 Def./MEY based on 5,000 yards (4570 meters) per section beam (total 8 section beams). The yarn on section beams is rebeamed through a Cocker slasher but without applying size. Three -inch loom beams are woven on three SO-inch Draper XD shuttle looms into 96 x 86 taffeta construction at 166 picks per minute with the type of -denier, 34-filament nylon filling yarn described in British specification 1,035,895. A total of 600 yards are woven (200 yards on each loom) with weave efliciency of 2.5 warp ends out per 100 yards vs. 4.0 warp ends out per 100 yards for commercially sized warp used as control. The remainder of these section beams are rebeamed on a conventional rebeamer (at y.p.m.) to 50-inch loom beams. The unsized yarn is then woven into 96 x 86 plain weave tafl'eta fabric at 200 picks per minute using commercial 70-denier, 34-filament nylon filling yarn on 47-inch Draper XD shuttle looms at the commercial mill referred to in Example 3 to provide 3008 yards of saleable fabric with an over-all weave efiiciency of 94.8%. (The mill performance of the yarn corresponded well with the direct weave performance of one package of the same yarn on a small scale laboratory loom used for performance test summarized in Table IX.)

Table V Process conditions:

Meter pump throughput 3.2 lbs./hr./end. Primary finish type N.

Cone. 12%.

Feed roll speed 1081 y.p.m. (988 m.p.m.).

1st draw roll speed 258$ y.p.m. (2363 m.p.m.).

Chest draw roll speed 3594 y.p.m. (3285 m.p.m.).

Chest roll temp 190:2 C.

Secondary finish type M.

Cone 20%.

Windup tension 18 gms.

Jet zone tension 10 gms. (approx.).

W indup speed 3425 y.p.m. (3130 m.p.m.).

Interlace jet-type Tandem Type B (Pos.

35, FIG. 5).

Air pressure 80 p.s.i.g. (5.6

kgJcmF).

Air flow 2.75 s.c.f.m./jet.

Air temperature 25 C. (approx.).

Table VI.Test yarn properties Single package:

APDC (100 readings)- Y cms. (after backwinding) 1.9 a" cms. (after backwinding) 0.62 CV (after backwinding), percent 0.32

TABLE 71.-Continued Denier 70.4 No. of filaments per yarn bundle 34 Tenacity, g.p.d. 5.36 Break elongation, percent 27.7 Initial modulus, g.p.d. at 10 elongationxlOO 27.5 Filament strength, g.p.f 11.1 Finish on yarn (weight basis)-- Primary, percent nonvolatile 0.73

Secondary, percent nonvolatile 0.32

Example An additional amount of the test yarn described in Example 7, on section beams, is loom beamed through the Cocker slasher and 0.75% afterwax is applied without any size. Three 50-inch loom beams are then woven on the same three Draper XD shuttle looms used for Example 4 in a 96 x 86 taffeta construction at 1 66 picks per minute with the same type filling yarn as described in Example 4. A total of 600 yards of fabric are woven with weave efliciency of 3.7 warp ends out per 100 yards vs. weave efficiency of 4.0 warp ends out per 100 yards for the commercially sized warp used as control.

Example 6 Yarns having a small number of filaments or large denier per filament, or both, are particularly diflicult to interlace. Nylon yarn of 200 denier and 20 filaments is one such material. This yarn is interlaced using the process shown in FIG. 5 with interlacing jet Type C (Table I) in the alternate position 37. Type Q finish (Table II) is applied by both the primary finish roll 27 and secondary finish roll 36 of FIG. 5. Operating conditions and interlace data are shown in Table VII. The test yarn is beamed by the silk system onto one loom beam 36 inches wide (4936 ends) without size or afterwax. The yarn is woven at 184 picks/min. on a Crompton-Knowles C-4 shuttle loom into 160 x 4-0 S-shaft warp-faced satin weave using 12/2 rayon as filling, making 409 yards of 36-inch wide fabric. The weave efiiciency is 1.5 warp ends out per 100 yards. The quality of the greige fabric was first grade.

Table VII Polymer throughput 5.4 lbs./hr./end. Feed roll speed (28) 579 y.p.m. (530 m.p.m.).

1st draw roll speed (31) 1215 y.p.m. (1110 m.p.m.). 2nd draw roll speed (33) 2093 y.p.m. (1920 m.p.m.). 2nd draw roll temp. (33) 200 C.

CV before backwinding 0.50 R (cm.) after backwinding 22 0 (cm.) after backwinding 4.0 CV after backwinding 0.57 Interlace retention (percent) 46 Tenacity (gm. per denier) 5.22 Filament strength (g.p.f.) 53.8

As a laboratory test of the Weavability of yarns, a modified silk-system warper was used to make warps 26 inches (66 cm.) wide from a single package of test yarn. A 26-inch wide Crompton-Knowles Model C5 loom was used to weave 9 yards (8.2 meters) of fabric.

Three-yard (2.7 meter) sections of each fabric were 'woven at increasing density (picks per inch) at settings indicated until the maximum density was reached in the final 3 yards. The loom settings for the major yarn counts were as shown in Table VIII.

1,035,859 published July 13, 1966.

The abbreviation BF is used to indicate broken filaments in the Warp. There may be so many broken filaments when the loom first starts that weaving is impossible. Start-up problems are designated start if temporary. Excellent products which are fully acceptable for commercial weaving will weave even at the highest picks per inch without any operating difiiculties. Samples which are on the borderline between weavable and not weavable and, therefore, are of the most interest for defining the limits of weavability, produce broken filaments or broken ends which can be counted, and the broken ends stop the loom. Therefore, broken filament counts and loom stops can be used as measures of relative operability on these borderline samples. A rating system ranging from Excellent through Good, Fair, Poor to Inoperable was used for over-all weaving performance.

The above weavability test was used to evaluate a variety of 66-niylon yarns.. Table IX summarizes the results together with APDC measurements and other yarn properties. The type of interlacing jet (Table I), air pressure, yarn speed and tension used to interlace the yarns are indicated, the processing being similar in other respects to that for comparable yarns of the previous examples.

Examples 7-15 illustrate the effect of variations in finish on yarn properties. Examples 16-21 illustrate 40- denier and ZOO-denier yarns of this inpention. All of the filaments had round cross-sections except those of Examples 16, 17, and 20, which were trilo-bal as disclosed 7 0 (in in Holland US. Pat. No. 2,939,201.

TABLE IX Example No 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 70. 8 '1. 4 70. 9 69. 8 69. 8 70. 2 70. 7 71. 3 71. 6 41. 0 40. 2 40. 7 40. 6 41. 5 204. 3 Yum denier 34 l 34 34 34 34 34 34 34 34 13 13 34 34 20 B B B B (0 (i (l 0) 0 Jet arran ement Air 1318855113 (p.s.i.g.) 80 60 0 80 80 8 8 60 100 60 72 Yarn speed (y.p.m.) 3, 425 3, 425 3, 425 3, 425 3, 425 3, 5 3, 425 3, 425 2, 950 2, 970 2, 970 2, 920 2, 920 2, 920 2, 000

Yarn tension (grams) 17 17 17 1B 18 l8 l8 18 1B 10 10 11 11 10 30 ii eiff N N g g 3, N 1; 1g 1 I; Concentration rcent) 12 12 1 Nonvolaties on Y arn (percent) O. 73 44 57 55 55 55 42 60 1. 19 1. 22 1. 15 1. 44 1. 60

1 532 2 1 M M M Q Q Q R R Q M M M M M M Concentration (percent) 20 20 20 20 20 20 20 20 20 20 20 20 20 Nonvolatlles on yarn (percent) 32 41 06 25 45 55 91 92 54 1. l8 1. 18 l. 01 l. 03 98 PAA on Yarn (percent) 41 4B Footnotes at end of table.

TABLE IXCntin11ed Example No 7 s 0 10 11 12 13 14 15 16 17 1s 10 20 21 Yarn properties:

X (515.) before beckwinding 1.0 2.2 2.5 2.0 1.0 1.0 1.5 1.0 1.3 2.3 2.2 1.8 2.0 1.0 2.0

(5511. before backwinding- 0. 66 0.33 0. 33 0.70 0.67 0.68 0.55 0.65 0.73 0. 01 0.73 0.56 0.56 0.50 1.5

2v bBiOie backwinding 0. 35 0.33 0.36 0.35 0. 35 0.37 0.31 0.34 0. 39 0. 30 0.33 0. 32 0.28 0. 31 0.52

X (5111.) after backwinding. 2.0 2.6 3.0 2.1 2.1 2.1 2.3 2.0 2.0 2.3 2.6 1.0 1.3 1.9 5.6

5' (5111.) after backwinding 0.72 1.1 1.3 0. 53 0. 76 0.52 0.05 0.67 0.60 1.2 1.0 0.54 0.57 0.56 3.3

0v after backwinding 0.36 0.41 0.41 0.32 0.35 0.30 0.40 0.33 0.30 0.44 0 3s 0. 20 0.31 0.30 0.67

lnteilace retention (percent)- 95 B4 83 95 91 91 78 95 90 84 84 95 100 100 52 Tenacity (grams/denier)" 4. 96 5. 53 5.05 4.30 4.00 5.13 5.23 4.50 4.73 4.56 4. 43 4.75 4.30 4. 4.77

Filament strength (g.p.f.) 10.3 11.7 10.5 10.0 10.2 10.7 10.0 10.2 10.1 14.4 13.3 5.69 5.73 5. 43 43.7 Weaving performance:

Over-all weave rating Q) Warp-caused 100m stops:

ForBUpicks/lneh 0 4 0 2 0 0 0 0 0 3B]? 0 SEE 0 0 2131 For 00 pieks/inch 0 0 0 0 0 0 lBF 0 0 0 0 0 0 0 For 100 picks/inch 2 0 lBF 0 0 0 0 0 0 0 0 0 0 0 I Tandem. 2 Single. 3 Good. 4 Fair. 6 Excellent. 6 Start. 7 3 Bi at picks/inch.

Additional poiyhexarnethyleneadipamide yarns having In the following examples, polyhexarnethyleneadipa relative viscosity of about 40 and containing a nominal amide yarns made by the process of Examples 22-24 with level of 0.5% titanium dioxide as delustrant are spunthe specific conditions shown in Table XI were beamed drawn and interlaced on equipment shown schematically into three band warps and were woven into 100 x 80 fabin FIG. 5 to form yarns of this invention. The tandem 30 ties on a Draper shuttle loom. The same -34 filling jets are in Position 35. Processing conditions and yarn yarn as in Table VIII was used for the first two yards. The properties are shown in Table X. In contrast to the exremaining 7 yards were woven Without filling yarn in the amples of Table IX, however, the yarns are rebeamed onto shuttle. The worked warp yarns were then re-evaluated 300 yard loom beams and woven into 96 X 86 tafleta fabric on the APDC meter for interlace retention after weaving. on two diiferent types of commercial shuttle looms. Warp- 35 The chief diiference between the processes for making caused stops with sized interlaced commercial warp yarn the yarns of the following examples is the primary and of the prior art are normally three stops per hundred yards secondary finishes. The APDC (X) before backwinding on the Draper XD loom and seven stops per hundred was practically the same for all 3 yarns but the effect of yards on the Draper X-3 loom. The percentage following 40 diflerent finishes is evidenced by the values after backthe finish type indicates the amount of finish non-volatiles in a water dispersion.

winding and after weaving. Example 25 used normal lubricating finishes (Primary Type N, Secondary Type M).

TABLE X [Additional examples of tightly interlaced (semi-dull) yarns in shuttle looms] Examples 22 23 24 Yarn denier 70 70 70 No. 01 filaments. 34 34 17 Interlacing 1012s.. B B B Jet arrangement Tandem Tandem Tandem Air pressure (p.s.i.g.) 81) Primary finish:

yp Q Q Concentration (percent) 8 2 8 Secondary finish:

T5; 0 Q R Q Concentration (percent) 8 10 8 Yarn speed (y.p.m.) 3, 500 3, 500 3, 000 Yarn tension (after roll 36), g 18 18 1B Yarninterlalce within package:

X (em.) before backwinding 2. 12 2. 06 2. 57

a(crn.) before backwinding .73 62 93 X (cm.) after baekwinding 2. 19 2. l5 3. 58

a" (0111.) a iter backwinding" .75 .61) 1. 73

CV =1r/X 0. 34 0. 32 D. 49

Interlace retention, percent 97 96 Tenacity, g.p.d 5. 2 5. 2 5. 2 Filament strength, g.p.f 10. 7 10. 7 21. 4 Weaving performance:

Loom type (Draper) X D X-3 X D X-3 X D X-3 Weaving speed (picks/min.) 172 200 172 200 172 200 Warp-caused stops/100 yds 1 4. 5 4. 5 5. 5 10 4 Over-all weave rating Excellent Good Good Each value represents 24 packages X100 splits per package.

25 Example 26 used the preferred Type Q/ Type Q combination and the Example 27 used the preferred Type T/Type R finishes.

TABLE XI Example 25 26 27 Yarn denier 70 70 70 No. of filaments 34 34 34 lnterlaeing jet (type) B B B .1 ct arrangement. Tandem Tandem Tandem Air pressure (p.s.i.g.) 7 80 Yarn speed (y.p.m.). Yarn tension (grains) i 7 8 8 Primary finish:

'lype N Q '1 Concentration cent 8 8 2 Nonvolatiles on yarn (percent)-.- 0.3-1 0.55 Secondary finish:

Type M Q R C(nicentration (percent) 20 8 ll) Nonvolatilcs on yarn (percent) 0. 85 32 Yarn properties:

X (ems) before backwiding 1 1.81 1. 8/6 1. 81 0 (runs) before backwinding (1.59 0.66 0. 54 before htLCkWlIldlHg." 0.32 0.35 0.20 X terns.) after backwinding 2. 23 2.13 1. 93 a (t'lllS.) after backwinding 0. 87 0.76 0.54 (.V after backwinding. 0. 39 0. 35 0. 27 lnterlace retention (percent) after E weaving 81 87 J4 X" (0111s.) after weaving... 4. 03 2. 68 2.12 a" toms.) after weaving. 2. 70 1. 41 0.84 UV after weaving 0. 07 0. 52 0. 40 lnterlacc retention (percent) 55 60 86 *See the following table:

Nonvolatiles on yarn excluding PAA 0. 04 lolyacrylic acid on yarn 0. 35

Total nonvolatiles 1. 20

Additional polyethylene terephthalate yarns are made by the process conditions listed in Table XII, other conditions being similar to those in Example 3. The polymer of Examples 28 to 30 is polyethylene terephthalate having a relative viscosity of about 26.5 with about 0.45% T102. The material of Example 31 is copolymer of about 19.5 relative viscosity containing about 98% polyethylene terephthalate and about 2% sodium 3,5-dicarboxybenzene sulfonate with about 0.45% TiO TABLE XII Example No 28 20 30 31 Yarn denier; 50. 7 40. 3 150. 2 101. 0 No. of Iilaments 27 34 50 Interlaeingjet (t A A A Jet arrangement..." Single Single Single Single Air pressure (p.s.i.g.) 90 U 90 00 Yarn speed (y.p.m.) 3, 300 3, 300 2,400 3,000 Yarn tension tgms.) 16 133:2 20 Yur properties:

X (cnr) before backwinding 2. 8 2. 7 3. 0 2.1 0' tom.) before hnckwinding 1. 37 1. 10 1. 23 0. 76 before hackwinding 0. 40 0. 41 0. 40 0. 36 X (c111,) after backwiuding. 2. 7 2. 4. 4 2. 5 17" (cm.) before backwinding 0.00 0.76 2.07 0.81 UV after backwinding. 0. 33 0. 30 0. 47 0. 33 Interlace retention (percent) 103 108 68 84 Tenacity terns/den) 4.3 3.8 4.2 3. 1 Filament strength (gpt)... 8. 07 5. 08 18.6 6.25

Example 32 An additional polyethylene terephthalate yarn is made by the process conditions listed in Table XIII, other conditions being similar to those in Example 3. The improved interlace retention is believed to be due chiefly to the different secondary finish. The process and apparatus are like those in FIG. 7 and Example 3 except for the type of jet and the location in position 99 between the enclosure 47 and finish roll 48. The finish applied via finish roll 48 is Type S (Table II). The dispersion consists of parts Type S to 90 parts water by weight. Processing conditions and yarn properties are listed in Table XIII. The finish non-volatiles by weight on the yarn approaching the interlacimng jet are 0.55% and the finish non-volatiles applied to the yarn at finish roll 48 are 0.41% giving a total finish on yarn of 0.96%. This yarn is beamed into warp without twist or size and is mounted on a Crompton-Knowles 26 shuttle loom. The same yarn is used for filling. A 96 x 86 taffeta fabric sample 26 inches wide by 8 yards long is woven with no loom stops.

Table XIII Yarn denier 70.3 No. of filaments 34 Interlacing jet type B Jet arrangement Single Air pressure (p.s.i.g.) 91 Yarn speed (y.p.m.) 3200 Yarn tension (grams) 22 Yarn properties:

X (cms.) before backwinding 2.3 o' (cms) before backwinding 0.91 CV before backwinding 0.40 X (ems) afterbackwinding 2.2 a" (cms) after backwinding 0.75 CV after backwinding 0.34 Interlace retention (percent) 104 Tenacity (gms./den.) 4.1 Fliament strength (g.p.f.) 8.4

I claim:

1. Compact interlaced yarn which weaves satisfactorily as warp in automatic shuttle looms without size or twist, the yarn consisting of continuous filaments interlaced together in a compact coherent structure characterized, when evaluated by the APDC test, by having a. value for X'+a' in centimeters of less than 0.17 (B/N)+4.0 and a coefficient of variation (if/X) of less than 0.039 (d.) +0.33, where X is the average of 100 APDC readings determined on a representative sample after backwinding, a" is the standard deviation of the APDC readings, B is the breaking strength of the yarn in grams, N is the number of filaments and (d.) is the denier per filament, said yarn having a breaking strength of at least 4.0 N and at least of said filaments having strengths of at least 2.0 grams per denier.

2. Compact interlaced yarn as defined in claim 1, having less than 10 defects per million end yards of yarn when tested for projecting filaments with a defect analyzer.

3. Compact interlaced yarn as defined in claim 1 wherein the yarn is 20 to 250 denier and consists of at least 7 filaments of 1 to 10 denier per filament.

4. Compact interlaced yarns defined in claim 1 wherein the filaments are composed of polyethylene terephthalate.

5. Compact interlaced yarn as defined in claim 1 wherein the filaments are composed of polyhexamethyleneadipamide.

6. Compact interlaced yarn as defined in claim 1, having an interlace retention of at least after backwinding.

7. Compact interlaced yarn as defined in claim 1 wherein the value of X'+a' is less than 0.17 (B/N)+1.5.

8. In the process for spinning, drawing and interlacing synthetic polymer filaments to produce multifilament yarn for shipment without any twisting operation, the improvement for producing interlaced yarn which weaves satisfactorily as warp in automatic shuttle looms Without twisting or sizing the yarn and has no more than 10 defects per million end yards of yarn in a conventional test for projecting filaments with a defect analyzer, wherein the improvement comprises jetting gas under a pressure of 60 to pounds per square inch gage pressure through a pair of adjacent orifices to form intersecting streams of jetted gas, the adjacent orifices being arranged in a side-by-side alignment perpendicular to the direction of yarn travel, feeding a group of at least 7 filaments having an average filament strength of at least 4.0 grams per filament through the intersecting streams under a tension between 0.1 and 0.4 gram per denier to interlace the filaments into a yarn and then winding up the yarn to form a package, applying a finish to the filaments prior to interlacing to provide between 0.3 and 3.0% by weight of finish non-volatiles on the filaments fed to the intersecting streams, and rapidly traversing the yarn from side to side so that the filaments are oscillated in the intersecting streams to produce a compact interlaced yarn characterized by having a value for X'+a in centimeters of less than 0.17 (B/N)-|4.0 and a coefficient of variation (07?) of less than 0.039(d.)+0.33, where Y is the average of 100 APDC readings determined on a representative sample after backwinding, 0' is the standard deviation of the APDC readings, B is the breaking strength of the yarn in grams, N is the number of filaments and (d.) is the denier per filament.

9. A process as defined in claim 8 wherein the yarn is mechanically traversed from side to side so that the filaments are oscillated in said intersecting streams.

10. A process as defined in claim 8 wherein the yarn is rapidly traversed from side to side by a traverse guide while winding up the yarn and the intersecting streams are located so that the filaments are oscillated in said streams.

11. A process as defined in claim 8 wherein the yarn is pneumatically traversed by a tandem jet arrangement so that the filaments are oscillated in said intersecting streams.

12. A process as defined in claim 8 wherein two pairs of intersecting streams arranged in tandem cooperate to traverse the yarn rapidly from side to side so that the filaments are oscillated in intersecting streams.

References Cited JOHN PETRAKES, Primary Examiner U.C. Cl. X.R. 

